1. Field of the Invention
The present invention relates to a continuous pattern printing system, and more particularly to a system which can print a continuous pattern on a web such as paper and cloth by using image data representing a basic figure the continuous pattern being formed by joining a plurality of the basic figures consecutively side by side in both vertical and horizontal directions.
2. Description of the Related Art
In most cases, the pattern printed on a web such as wrapping paper, wallpaper and cloth is not designed as a single pattern to be printed on its entirety, but a basic figure, which is generally rectangular, is designed and a plurality of the basic figures are joined consecutively, side by side, in both vertical and horizontal directions so as to form a continuous pattern. A printing plate including the basic figures as joined is made, and printing is performed using this printing plate. The processing for joining two adjacent basic figures is performed by a method disclosed in, for example, JP-A-1-171880.
This method gradually reduces the mesh density in the neighborhood of the boundary between the adjacent basic figures and overlaps adjacent areas thereof so that the boundary between them is not clearly revealed.
This prior art method can join basic figures smoothly so that the boundary is not clearly revealed. However, it has the following defect. When printing a pattern of basic figures joined by shifting them little by little in a horizontal or vertical direction, a discontinuity may appear at the boundary. Namely, only shifting the basic figures to be joined does not provide a continuous pattern at the boundary.